fix(ralph-loop): keep LLM in smart zone with fresh context per iteration

[edxeth]

The Problem: Context Window Overflow

The original ralph-loop implementation kept all iterations in a single session, causing the context window to fill up over time. This is exactly the problem described in "Why the Anthropic Ralph plugin sucks":

As LLMs receive more tokens, the relationships between tokens scale quadratically. Each additional token makes it harder for the model to process information and make good decisions.

Every LLM has a smart zone (first ~40% of context) and a dumb zone (remaining ~60%). The original implementation guaranteed you'd enter the dumb zone after just a few iterations:

Iteration	Context Usage	Zone
1	~20%	Smart
2	~35%	Smart
3	~50%	Dumb
4+	60%+	Dumb

The Solution: Fresh Context Per Iteration

This PR adds a default_strategy config option with "reset" as the new default:

Strategy	Behavior	Use Case
reset	Creates NEW session each iteration	Long-running loops, production work
continue	Keeps same session	Short tasks, debugging

With reset, each iteration starts with a fresh context window. The LLM always operates in the smart zone:

Iteration 1: Fresh context → Smart zone → Commit
Iteration 2: Fresh context → Smart zone → Commit  
Iteration 3: Fresh context → Smart zone → Commit
...

This matches how the original bash-loop Ralph works:

while :; do cat PROMPT.md | claude-code ; done

Each invocation = fresh context.

Changes

Core Feature

• New default_strategy config with reset (default) and continue options
• --strategy flag for per-loop override: /ralph-loop "task" --strategy=continue
• Strategy stored in loop state - persists across iterations

Bug Fixes

• Skip todo-continuation-enforcer when ralph-loop is active - prevents hook conflicts
• Conditional prompt prefix - reset allows keyword detection (new session needs mode injections), continue skips it (mode already applied)

Implementation

• TUI session switch via raw API call to /tui/select-session
• Strategy parsed from command arguments in both chat.message and PreToolUse handlers

Usage

Config (default for all loops):

{
  "ralph_loop": {
    "enabled": true,
    "default_strategy": "reset"
  }
}

Command (per-loop override):

/ralph-loop "Build feature X" --strategy=continue --max-iterations=10

Testing

• 42 ralph-loop tests pass
• 37 todo-continuation-enforcer tests pass
• Manually verified both strategies work correctly

References

• Everything is a Ralph Loop - Original concept
• Why the Anthropic Ralph plugin sucks - The problem this PR fixes
• 11 Tips for AI Coding with Ralph Wiggum - Best practices

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Reopen Note

This PR is a direct reopen of #1348 from a dedicated feature branch (edxeth:pr-1348-reopen) because the previous PR used dev as both head and base branch name context.

• Original PR: fix(ralph-loop): keep LLM in smart zone with fresh context per iteration #1348
• Reopened to satisfy branch policy (feature branch -> dev)
• Commit history/content preserved (same head commit and commit set)

[cubic-dev-ai]

No issues found across 20 files

Confidence score: 5/5

• Automated review surfaced no issues in the provided summaries.
• No files require special attention.

_{Auto-approved: PR only adds new feature for context strategy with thorough tests and no regressions detected.}